diff --git a/types.go b/types.go
index 9b164fd2..22db773b 100644
--- a/types.go
+++ b/types.go
@@ -1398,17 +1398,6 @@ func StringToTime(s string) (uint32, error) {
 	return uint32(t.Unix() - (mod * year68)), nil
 }
 
-// TimeToUint32 translates a time.Time to a 32 bit value which
-// can be used as the RRSIG's inception or expiration times.
-func TimeToUint32(t time.Time) uint32 {
-	// TODO(mg): rfc1982
-	mod := (t.Unix() / year68) - 1
-	if mod < 0 {
-		mod = 0
-	}
-	return uint32(t.Unix() - (mod * year68))
-}
-
 // saltString converts a NSECX salt to uppercase and
 // returns "-" when it is empty
 func saltString(s string) string {
diff --git a/zone.go b/zone.go
index d7af9d66..76afa937 100644
--- a/zone.go
+++ b/zone.go
@@ -369,3 +369,13 @@ type uint16Slice []uint16
 func (p uint16Slice) Len() int           { return len(p) }
 func (p uint16Slice) Less(i, j int) bool { return p[i] < p[j] }
 func (p uint16Slice) Swap(i, j int)      { p[i], p[j] = p[j], p[i] }
+
+// TimeToUint32 translates a time.Time to a 32 bit value which                      
+// can be used as the RRSIG's inception or expiration times.                        
+func TimeToUint32(t time.Time) uint32 {
+	mod := (t.Unix() / year68) - 1
+	if mod < 0 {
+		mod = 0
+	}
+	return uint32(t.Unix() - (mod * year68))
+}